Someday when the globe runs out of freshwater, you might want to know how to remove salt from saline water.   Get to Know What Is Salt Water   Salt water is water that contains significant amounts of dissolved salt, and we usually express its salt saturation in “parts per thousand” or ppt. For example, seawater has a salt concentration of about 35 ppt, meaning there are about 35 grams of salt per one liter (or kilogram) of seawater.     Different levels of dissolved salt concentration can decide the water type as freshwater, brackish water, saline water and briny water.     Edible water must keep the saline concentration lower than 0.05 ppt. The less saline substances, the better the quality of drinking water. The optimum value of ppt for drinking water is zero. For agriculture...